docs: def findAllByRow(self, target):
          """ Returns an array of rows in the region (defined by the raster), each
          row containing all matches in that row for the target pattern. """
          row_matches = []
          for row_index in range(self._raster[0]):
              row = self.getRow(row_index)
              row_matches[row_index] = row.findAll(target)
          return row_matches